1. Field of the Invention
The present invention relates to an endocardial lead adapted to be implanted within a chamber in a human organ, such as the heart, with the lead comprising a lead body and an electrode assembly having projections extending therefrom with saw teeth on the projections which can be in the form of tines or fins, for enhancing, facilitating and enabling the electrode assembly to lodge itself in trabeculae in heart chamber, such as the atrium or ventricle, for holding the electrode assembly in a desired position where an electrode tip of the assembly bears against and makes good electrical contact with an endocardial wall of the heart chamber.
2. Description of the Prior Art
Heretofore, it has been proposed to provide a transvenous body implantable lead having a tip electrode at the distal end thereof and having tines extending from a sheath of a lead body just behind the tip electrode. These tines extend angularly, rearwardly and outwardly from the sheath.
A leading example of such a transvenous body implantable lead is disclosed in U.S. Pat. No. 3,902,501 issued to Paul Citron and Eugene A. Dickhudt on Sept. 2, 1975, the disclosure of which patent is incorporated herein by reference.
Another example of such a transvenous body implantable lead is disclosed in U.S. Pat. No. 3,939,843 issued to Nicholas P.D. Smyth on Feb. 24, 1976 the disclosure of which patent is incorporated herein by reference.
The lead of the Smyth patent can have from 3 to 9 tines with the tines arranged axially and circumferentially around the lead body at the distal end thereof. Such tines are made of a plastic flexible material so that they can bend rearwardly, downwardly when the lead body is inserted through a vein to a heart chamber.
It has also been proposed to provide an electrode having a metal barbed electrode tip with a barb extending rearwardly of the tip. Such electrode tip is part of an electrode assembly mounted on the end of a myocardial sutureless unipolar lead and the barbed electrode tip is adapted to be inserted through the outer wall of the heart and embedded in the heart wall tissue.
Also, it is known of course, to provide saw teeth on saw blades and in devices utilized to hold bait, such as in an animal trap, a mouse trap or a fish hook assembly.
However, heretofore it has not been proposed to provide at least one saw tooth or a saw teeth formation on an outer facing edge of a projection projecting from an insulating sleeve of a distal electrode assembly mounted at the distal end of an endocardial lead.
As will be described in greater detail hereinafter, the endocardial lead of the present invention and particularly, the electrode assembly at the distal end thereof, differs from the electrode tip and tine construction at the distal end of the transvenous lead disclosed in the Smyth U.S. Pat. No. 3,939,843 by providing projections at the distal end of the lead that have at least one saw tooth or saw teeth formations thereof, the projections being in the form of tines or fins.